1. Field of the Invention
The present invention relates to an improved structure of a temperature-sensing tube for an aquarium, and especially to a structure in which influence on the accuracy of temperature sensing by noises generated by the interior electric circuit elements of the temperature-sensing tube can be prevented by means of connecting and heat sinking through an interior temperature sensitive switch.
2. Description of the Prior Art
Water temperature in an aquarium can be changed by influence of ambient weather (such as hot summertime or cold winter). Therefore, for control of the temperature in the aquarium, a temperature-sensing tube with a heating device therein has to be used to assure that cultivated fishes can survive in the aquarium.
Although maintaining the water temperature is useful, when cultivating different fishes in an aquarium, different temperatures may be used. For example, fresh-water fishes shall be cultivated in an aquarium with a higher temperature; while deep-water fishes shall be cultivated n an aquarium with a lower temperature. Hence, a normal temperature-sensing tube includes an electric heating device capable of generating a specific temperature to adjust the water temperature. Such a temperature-sensing tube is provided with related members, such as an electric circuit board, a temperature-sensing element, and a temperature sensitive switch. However, such a conventional temperature-sensing device is subject to influence of the temperature generated by operation of the electric circuit board and other elements to result inaccuracy of sensing. For example, if the temperature set originally is 15xc2x0 C., a temperature-sensing tube may have the temperature sensitive switch turn off when water temperature reaches 12xc2x0 C., resulting in undesirable inaccuracy of sensing.
U.S. Pat. No. 6,097,007 titled xe2x80x9cAquarium water temperature controllerxe2x80x9d has solved such trouble of inaccuracy of sensing of a temperature-sensing tube. The known device has a thyristor activated or turned off in different potentials by way of connecting a bridge circuit having a heat sensitive resistance with a comparator, as well as of triggering an analog circuit by a bias voltage generating circuit, thereby water temperature can be more accurately sensed. However, such a design makes the related electric circuits of the whole temperature-sensing tube complicated, and makes the cost of production high.
The object of the present invention is to provide an improved structure of a temperature-sensing tube for an aquarium, wherein, a heat-sinking piece is welded to a temperature-sensing switch, the heat-sinking piece preferably being coincident with the shape of, and kept close to the inner wall of a temperature-sensing tube, so that it can transmit the temperature generated by the temperature-sensing switch to the wall of an outer pipe to contact the water in the aquarium, to thereby prevent probably error of temperature sensing. Therefore, a more accurate temperature sensing function can be obtained with more economical cost.
The present invention will be apparent in its novelty and other features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.